AIDS-associated Kaposi's sarcoma and the mechanisms of interferon alpha's activity; a riddle within a puzzle

As yet, the pathogenesis of Kaposi's sarcoma in the context of the acquired immunodeficiency syndrome (AIDS) is not completely understood; this is also true for the mechanisms of action of interferon-alpha against this tumour. The present review focuses on recent developments that may provide some further insight into these issues. These include the angiogenesis of the tumour and the possible role of growth factors, such as the HIV-transactivating (tat) gene product and interleukin-6, the possible meaning of immunomodulating activities of interferon-alpha, such as the rise in the number of CD4+ cells and the increase in beta 2-microglobulin serum concentrations in patients whose tumours respond to treatment, and the observed association between interferon's antiretroviral activity and tumour responses.